Although some lubricants (like the slim strip on the razor in our top photo) are used at reasonably cool and constant temperatures, many have to work in engines and machines at very high temperatures. Car engines use thick, syrupy oils for lubrication because these stay liquid at over 300°C (570°F), which is hot enough to survive the kind of temperatures that engine parts heat up to. Water would quickly evaporate and turn to steam in those conditions but it also makes metal parts turn rusty, so it's not really a good choice for a lubricant. for that you need a good berita otomotif luar negeri

Often, lubricants have to work well at a range of temperatures. For example, in a chilly country like Iceland or Switzerland, car axle lubricants need to do their job both when the car is just starting from cold and when it's been running for a while. In practice, that could mean a wide range of operating temperatures from -10°C to 100°C (-14 to 212°F). Lubricants are much like any other substance: the colder they get, the harder, more solid, and less fluid (more viscous or "treacly") they become. Sometimes, that means they work less effectively: the poorer performance of lubricants at lower temperatures is one of the reasons why engines and transmissions are less efficient before they've properly warmed up. Pasang gorden jakarta

On the other hand, the hotter you make a lubricant, the thinner and less viscous (more runny) it becomes. Although that might sound like a good thing, it isn't always. On heavy-duty machines working slowly at high power, you need a thicker, more durable layer of lubrication, and a low-viscosity lubricant isn't going to be helpful. The thinner a lubricant becomes, the more likely a machine is to seize up. Usually, there's a critical temperature above which lubricants no longer form a strong and effective coating that sticks to the parts they're touching, performance falls off dramatically, and seizure becomes an alarming possibility.

So designing lubricants involves a careful study of the conditions under which particular engines and machines operate, including speeds, powers, and maximum and minimum temperatures, and a balance between performance, efficiency, and durability. In case you're wondering, the science of friction, lubrication, and surface wear is called tribology. So next time you meet a tribologist on your travels, you'll know exactly what to talk about!